This is an excerpt from Assessment and Treatment of Muscle Imbalance by Phillip Page,Clare Frank & Robert Lardner.
Muscle Length Assessment Technique
Muscle length testing involves elongating the muscle in the direction opposite of its action while assessing its resistance to passive lengthening. Precise testing requires that one of the bony attachments of the muscle (usually the origin) be in a fixed position while the other bony attachment is moved passively in the direction of lengthening the muscle. In other words, muscle length testing assesses the resistance to passive movement. This is in contrast to typical flexibility or ROM testing. The actual ROM can be measured for documentation purposes, but it gives limited clinical information in muscle imbalance syndromes. The most valuable clinical information is the muscular end feel and the location of the ROM end feel. The elongation of the muscle should be performed slowly to avoid eliciting a quick stretch of the muscle spindle and subsequently inducing a twitch response and muscle contraction. In addition, for the best accuracy and precision, muscle length testing should be performed when the patient is not in acute pain in order to avoid pain inhibition and muscle guarding. In summary, there are four steps to assessing muscle length:
1. Ensure maximal lengthening of the muscle from origin to insertion.
2. Firmly stabilize one end (usually the origin).
3. Slowly elongate the muscle.
4. Assess the end feel.
Following are the procedures for testing key muscles. Clinicians do not have to perform muscle length testing on every muscle listed; instead, they should assess the muscles that the postural and movement pattern analysis indicate as being possibly tight. Once tight muscles have been identified, the clinician can establish a muscle imbalance pattern (if present) and begin to look for causes of the tightness. Table 7.1 provides the normal results of muscle length for flexibility testing.
Table 7.1 Normal Results of Muscles Tested for Length
|Muscle||Normal ranges or end feel|
|Iliopsoas||0° hip extension, 10° with overpressure|
|Rectus femoris||90° knee extension, 125° with overpressure|
|TFL-IT band||0° hip abduction (neutral), 15°-20° with overpressure|
|Adductors||0° hip abduction (neutral), 20°-25° with overpressure in the modified Thomas test position
45° hip abduction in supine position
|Hamstrings||80° hip flexion with contralateral leg extended
90° hip flexion with contralateral leg flexed
|Triceps surae||0° ankle dorsiflexion|
|Quadratus lumborum||Thoracolumbar curve should be smooth and gradual|
|Piriformis||Gradual soft end feel|
|Upper trapezius||Gradual soft end feel|
|Levator scapulae||Gradual soft end feel|
|SCM||Gradual soft end feel|
Sternal portion (lower fibers): with shoulder abducted at 150°, arm should be
horizontal to table and 15°-20° with overpressure
Sternal portion (midfibers): with shoulder abducted to 90°, arm should be horizontal
to table and 30° with overpressure
Clavicular portion: with shoulder abducted to 60°, arm should hang freely over table
|Paraspinals||Schober's test: excursion of >2.4 in. (6 cm)|
The muscles of the lower quarter include those of the leg, pelvis, and lower back. The muscles prone to tightness are those involved in maintaining a single-leg stance (Janda 1987). Tightness of the hip flexors and tightness of the thoracolumbar extensors are hallmark signs of Janda's LCS.
Modified Thomas Test for Hip Flexor
The modified Thomas test (figure 7.2, a-e) allows the clinician to assess four different muscles prone to tightness namely, the one-joint hip flexor, iliacus and psoas major, and the two-joint hip flexors, rectus femoris and TFL-ITB. Tightness of the hip flexors limits hip hyperextension in gait and may cause an anterior pelvic tilt. Weakness of the gluteus maximus often is due to facilitation of the hip flexors.
The patient is asked to sit on the edge of the table, with the coccyx and ischial tuberosities touching the table and one foot on the floor. Then, the patient is asked to flex the opposite hip and knee toward the chest and maintain the position with the hands (see figure 7.2a).
The clinician stands beside the leg not being tested, facing the patient. While supporting the patient by placing one hand on the midthoracic spine and the other on the knee, the clinician passively rolls the patient down to the table to the supine position. The clinician needs to ensure that the patient's knees are flexed, lumbar spine is flexed, and pelvis is in posterior rotation to fix the origin of the hip flexors.
The clinician passively lowers the tested leg until resistance is felt or movement at the pelvis is detected. With the patient's thigh in the final resting position, the clinician observes whether it is in neutral and parallel to the table or abducted. A normal length of the one-joint hip flexors with the lumbar spine and sacrum flat on the table is indicated by the posterior thigh touching the table (0° of hip extension). With slight overpressure, the thigh should reach 10° to 15° of hyperextension (figure 7.2, b-c). Prominence of a superior patellar groove (figure 7.2d) suggests a short rectus femoris, while prominence of a lateral IT groove suggests a short IT band (see figure 7.2e).